{"action":"Upgrade github.com/nats-io/nats-server/v2 to 2.11.12 or later.","affected":[{"fixed":"2.11.12","introduced":"0"},{"fixed":"2.12.3","introduced":"2.12.0-RC.1"}],"component":"github.com/nats-io/nats-server/v2","cve_ids":["CVE-2026-27571"],"ecosystem":"Go","epss":0.00542,"exploited":false,"fixed_versions":["2.11.12","2.12.3"],"ghsa_id":"GHSA-qrvq-68c2-7grw","id":"tcs_01M5KFKJ8TX24JX887BKGGPB3Q","modified_at":"2026-09-10T03:50:59.521985809Z","published_at":"2026-02-24T16:04:53Z","references":["https://osv.dev/vulnerability/GHSA-qrvq-68c2-7grw","https://github.com/nats-io/nats-server/security/advisories/GHSA-qrvq-68c2-7grw","https://nvd.nist.gov/vuln/detail/CVE-2026-27571","https://github.com/nats-io/nats-server/commit/f77fb7c4535e6727cc1a2899cd8e6bbdd8ba2017","https://github.com/nats-io/nats-server","https://github.com/nats-io/nats-server/releases/tag/v2.11.12","https://github.com/nats-io/nats-server/releases/tag/v2.12.3","https://pkg.go.dev/vuln/GO-2026-4533"],"severity":{"label":"medium","score":5.9},"sources":[{"source":"osv","source_id":"GHSA-qrvq-68c2-7grw","url":"https://osv.dev/vulnerability/GHSA-qrvq-68c2-7grw"}],"summary":"nats-server websockets are vulnerable to pre-auth memory DoS"}